Insulating-coupling



(No Model.)

L. MGGARTHY. INSULATING COUPLING.

No. 468,773. Patented Fab. 9, 1892.

da r.. s 9 ff l Z 40 v0 .,fw/ f /f 0d C, l w l da rm Flg E 5 E W M UNITED STATES PATENT OFFICE.

LOUIS MOOARTHY, OF BOSTON, MASSACHUSETTS.

lNSULATlNG-COUPLING.

SPECIFICATION forming part of Letters Patent No. 468,773, dated February 9, 1892.

Application fled October 19, 1891. Serial No. 409,111. (No model.)

To all whom t may concern.-

Be it known thatI, LOUIS MCOARTHY, a citizen of the United States, residing at Boston, in the countyof Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Insulating-0ouplings, of which the following is a specification, reference being had therein to the accompanying drawings.

It is common to construct insulating-pipe couplings for use in connection with gasoliers and the like of two metallic portions, which consist of tubes or nipples that are properly threaded in order that they may be screwed onto the ends of the gas-pipes which are to be connected, the said tubes each being provided with a flange. Between the proximate faces of the flanges is placed a mass or layer of insulating material, the whole being held together by bolts, which pass through the flanges and through the interposed insulating-layer, or by other securing devices. These insulating-couplings or insulators are objectionable, in that the edges of the flanges are liable to be connected electrically in consequence of the deposition of moisture on such edges and the edges of the interposed layer of insulating material. It is also common in wiring the fixtures to pass the conducting-wires over the projecting edges of the flanges and then draw the wires tightly against the said edges. Vthen this has been done, if the covering of the wires becomes broken in any way a circuit is immediately established between the two flanges of the insulator and its efficiency destroyed.

My invention has for its object to produce an insulating-coupling which shall be free from these objections; and it consists of an insulator or insulatingcoupling, which is provided at the joint thereof with an Aoutside covering of insulating material, as hereinafter will be described, and as willbe pointed out in the claims which are appended hereto and made a part hereof.

I have shown my invention embodied in the best form now known to me in the accompanying drawings, in which drawings- Figure l is a View in cross-section lengthwise of a coupling having my insulating-covering applied to the joint thereof. Figs. 2, 3, and 4 are views of similar character showing modifications. Fig. 5 is a view in section on line 0c oc of Fig. 4.

The principal metallic portions of the insu- 5 5 lating-coupling are two short tubes or nipples a, these being properly screw-threaded to receive the ends of the gas-pipes which are to be connected, and being provided with flanges b at their proximate ends. Bet-Ween the 6o flanges is interposed a layer or mass h of insulating material, preferably sheetmica, which has been cut to the proper shape and provided with a central hole for the passage of the gas, the mica beinglaid and compressed 6 5 between the flanges h, and the whole being tightly clamped and secured together. Any suitable known securing means may be employed. Thus the partsmay be united by means of bolts f, which pass through the 7o vflanges and through holes in the interposed layer of insulating material. The bolts f may engage with the flange b and be insulated from one or both of the flanges ZJ in any well-known manner; but I prefer tohave the engagement and insulation effected in the manner shown. In the drawings the bolts are shown disposed in a manner to alternate in position-that is, the heads of alternate bolts are placed in holes g, which are pro- 8o vided in each flange b. In order to prevent the heads of the bolts from coming in contact with the flanges, each hole g is made considerable larger in diameter than the bolthead placed therein. Each head rests on the 8 5 interposed layer of insulating material, and the other end of each bolt is in engagement with the other one of the flanges b-as, for example, by being riveted thereto-as shown. Outside of the joint formed by the flanges b 9o and interposed layer of insulating material I place a covering or 'mass of insulating material, preferably one of the well-known coinpositions, the composition employed being molded around the joint in a plastic state, and then allowed to set and harden. The precise thickness or extent of the outer covering le of insulating material is not important so long as it is sufficient to thoroughly cover the joint and be strong and durable. `roo The joint covered in this way is wholly protected from short-circuiting by sweating or moisture or by impaired wires which may come in contact with it, is very durable, and

since the outer covering of insulating material may be smooth on the surface the insulating-coupling maybe easily cleaned and does not so readily retain dust or dirt as wou ld a coupling having holes or depressions in its surface or having projecting bolts or nuts.

I have shown in the drawings several modifications of myinvention.

Figure 2 shows an outer-covering layer 7c of somewhat different form in cross-section from what is shown in Fig. 1.

Fig. 3 shows an insulator in which the edges of the ianges b project beyond the interposed layer of insulating material h, one or both of the said projecting edges being provided with a groove l, which serves to retain the insulating-covering 7c securely in place, the groove or grooves being provided in case there are no other inequalities on the surface of the flanges b which would serve that pu rpose, or in addition to such other inequalities when desired. It is advantageous to have the retaining-points near the edge of the projections, so that in case the outer insulatingcovering becomes cracked or broken it will not so readily become detached as otherwise.

Fig. et shows au insulatorin which the outer covering 7l: is extended to the ends of the nipples or tubes b. If the covering be thus extended, it is desirable to make the tubes b hexagonal or octagonal in cross-section, so that a wrench may be applied to them outside of the covering 7c. It will be clear that this outer covering 7c of insulating materialis not limited in its application to any particular"Y form of insulatorror insulating-coupling, b ut may be applied irrespective of the precise form of the metallic portions of the insulator, and also irrespective of the means employed for securin g them together.

I do not herein separately claim an insulating-coupling for pi pes comprising two flanged tubes, a layer of insulating material placed between the iianges thereof, and a serles of securing-bolts alternately set with reference to the said flanges and having their heads alternately engaging with the opposite sldes of the said layer.

I have claimed this construction in another application for United States patent filed on the same date herewith.

Vhat I claim is- An insulating-coupling having the coupling portions thereof separated by an interposed layer of insulating material, devices whereby the whole is secured together, andan outer layer or jacket of insulating material whereby the joint is covered and whereby, also, the space between the outer parts of the coupling portions is prevented from becoming electrically bridged, substantially as and for the purposes set forth.

In testimony whereof I affix my signature in presence of two witnesses.

LOUIS MCCARTHY.

Witnesses: v

WM. A. MAcLEoD, ROBT. WALLACE. 

